The present invention relates to a sealing structure of a waterproof connector in which a connector housing having a connector housing body assembled with an inner member by inserting the inner member into the connector housing body is coupled with a mating connector housing through a seal ring in waterproof state.
FIG. 1 shows a known waterproof connector in which a connector housing 1 having a connector housing body 3 assembled with an inner member 4 is coupled with a mating connector housing 2 through a seal ring 7. In FIG. 1, the inner member 4 is inserted into a hollow 5 of the connector housing body 3 so as to be assembled with the connector housing body 3 and thus, the connector housing 1 is obtained. Meanwhile, the seal ring 7 has a plurality of rows of sealing bands 6 and is fitted into the hollow 5 such that the sealing bands 6 come into close contact with an inner periphery 11 of the hollow 5. Furthermore, the mating connector housing 2 is closely fitted into a gap formed between an inner periphery of the seal ring 7 and an outer periphery of the inner member 4 so as to be coupled with the connector housing 1 in waterproof state.
As shown in FIG. 2, the seal ring 7 has a substantially rectangular shape and a pair of fixing lugs 13 extend longitudinally outwardly from opposite ends of a top portion of the seal ring 7, respectively. Meanwhile, in the vicinity of an inlet of the hollow 5, a pair of slots 14 are formed on a side wall of the connector housing 1 such that the fixing lugs 13 are, respectively, engaged with the slots 14. The seal ring 7 is secured to the connector housing 1 through engagement of the fixing lugs 13 with the slots 14 so as not to be readily removed from the connector housing 1 when the connector housings 1 and 2 are coupled with and detached from each other.
In the known waterproof connector of the above described arrangement, the fixing lugs 13 are required to be provided at the top portion of the seal ring 7, namely in the vicinity of the inlet of the hollow 5 in order to obtain the waterproof function of the seal ring 7. Thus, the sealing bands 6 disposed below the fixing lugs 13 are not engaged with the hollow 5 and a peripheral wall of the mating connector housing 2 so as to be set free relative thereto.
Therefore, in the case where the connector housings 1 and 2 are coupled with and detached from each other, a large frictional force is produced between an inner face of the sealing bands 6 and a side wall of the connector housing 2. Especially, when the connector housing 2 is detached from the connector housing 1, an external force P is applied to an inner side portion of the sealing bands 6 due to the frictional force caused by detachment of the connector housing 2 from the connector housing 1. As the connector housing 2 is gradually drawn from the connector housing 1, the sealing bands 6 are set free on the inner face and therefore, is readily subjected to elastic deformation so as to be oriented improperly. Thus, when the connector housings 1 and 2 are coupled with and detached from each other repeatedly, an intermediate row of the sealing bands 6 is subjected to torsional deformation. As a result, such problems may arise that the waterproof function of the seal ring 7 deteriorates and the seal ring 7 is accidentally removed from the connector housing 1.